Apparatus for rotating spray guns to evenly paint non-planar surfaces



June 2, 1959 E. FABER 2,883,903

APPARATUS FOR RQTATING SPRAY GUNS T0 EVENLY PAINT NON-PLANAR SURFACESFiled Sept. 8, 1955 I 2 Sheets-Sheet 1 IN V EN TOR.

' gi /WEI? L. FABER WW M A TOR/YE S APPARATUS FOR ROTATING SPRAY GUNSTOEVENLY PAINT NON-PLANAR SURFA'OES Elmer L; Faber, Toledo, Ohio, assignorto Conforming Matrix Corporation, Toledo, Ohio, a corporation of OhioApplication September 8, 1955, Serial No.- 533,179

2'Claims. (Cl. 118-301) This-invention is an improvement in the artofspray painting. It provides a machine havingapparatusfor rotatingspray guns to evenly paint non-planar surfaces. The: invention isparticularly useful when embodied in machines for painting articlesthrough openings inmasks which are shaped to conform accurately to thesurfaces of the articles adjacent the openings and whichare tightlyfitted against such surfaces'before spray painting begins.

Such non-planar surfaces are usually quite small and may require anextremely smooth and evenly applied coat ofpaint. Heretofore, spraypainting machines have not been-equipped to rotate spray guns aboutcenters of curvature of such articles for the purpose of applying suchextremely smooth and evenly applied coats of paint.

Surfaces to be coated are not necessarily curved smoothly about the axisof rotation of the spray guns, but may have protuberances ordepressionsthe sides of which 'Will be coated more'eifectively because of the factthat the spray is applied from-the rotating guns. While the apparatusisparticularly effective for coating-non planar surfaces, the rotatingmovement of the guns does not preclude but rather enhances theireffectiveness for coating flat'surfaces.

It is, therefore, an object of this inventionto provide, in a spraypainting machine, means for rotating a sprayer for painting non-planarsurfaces.

Another object of the invention is to provide, ina spraypaintingmachine, a composite conduit rotatable on its own axis forrotating a sprayer and for supplying the sprayer With paint and air,wherebyv the sprayer directs a-spray substantially normally uponnon-planar surfaces,

A further object of the invention is to provide, in a spray paintingmachine, a sprayer support rotatable on its ownraxis for rocking asprayer and means for rotating thesprayer support, whereby, the sprayerdirects a spray substantially normally for painting non-planar surfaces.

Still another object of the invention is to provide, in a spraypainting. machine, a sprayer support rotatable on its own axisfor.rotating a sprayer directedto spray a non-planar surface positionedaxially of the sprayer support, the sprayer being so oriented as todirect a spray progressing around a conical path impingingnearlynormally upon all parts of the surface being painted.

More specific objects and advantages are apparent from. the followingdescription of preferred embodiments of the invention.

According to the invention, an improved spray painting machine includesa cabinet having an opening therein, a mask holder surrounding theopening, a sprayer so located within the cabinet as to direct a spraythrougha mask held by the holder, and means for rotating the sprayer forpainting non-planar surfaces.

Preferred embodiments of the invention are illustrated in theaccompanying drawings:

In the drawings:

Figure I is a side elevational view, partly in section, of a spraypaintingmachine having apparatuts for rotat- States Patent Patented June2, 1959 2. ing sprayers, a side parielbeing removed to show the.apparatus; I

Figure II is a reduced plan view of the cabinet and maskholder of thespray painting machine illustrated .in Figure .I.

Figure III is an enlarged vertical sectional VlW' show= ing the interiorof a rotatable composite conduit that is employed in the form of themachine illustrated in Figure I.

Figure IV is a more or less diagrammatic side elevational view, partlyin section, of a spray painting machine incorporating another embodimentof the app-aratusfor rotating sprayers, a side, panel being removed toshow the apparatus.

These specific figures and, the accompanying descrip tion are intendedmerely to illustrate the invention and not to limit its scope.

The mechanism of the invention, as illustrated in Figures I-III issupported in a cabinet 1 having removable side panels secured tohorizontal frame members 2 and 3, the panels being removed to showthemechanism. The frame member 2 preferably is a shelf which not onlyfunctions as a support for parts of the mechanism but also shields theparts which lie below itfrom deposits of paint.

The cabinet 1 has a roof 4 with an opening 5 thereinv and a mask holdingportion 6 surrounding the opening 5. The roof 4 is equippedwith clips7and 8 adapted to releasably fasten a mask 9 to the maskv holdingportion6 in such position that the mask overlies the opening 5 in theroof 4.The mask 9 has a matrix portion 10. formed to fit'accurately the. faceof anonaplanar. sur.-. faced or convexly curved article 11 to be coatedor dec.- orated. The mask 9 may partially cover the convexly curvedsurface of the article 11 vandhave a patterncut away, as shown inphantom in Fig. I, .to. permit the ap.-. plication of sprayed coating toone or more areas on the article corresponding to the cut away pattern.

The article 11 is held in place on the mask 9 by means of outer fingers12 and a center finger 13 forced against the article by the operation ofthepis ton of anair cylinder 14 carried by a'frame 15 mounted upon theroof 4 of the cabinet 1. The outer fingers 12 are horizontally ad;justable along arod 16 and the rod16 is vertically and pivotallyadjustableialong and about a piston rod 17 of the air cylinder 14.Normally, the rod 16-is pivoted ninety degrees from its position shownin Figure I to. keep the front of the machine clear. The rod 16 is shownin Figure I in abnormal position for purposes of. clear illustration.

The article 11 is given an evenly applied coat of paint by spraysemitted from a pair of sprayers 18 so located within the cabinet 1 as todirectthe sprays through the" mask 9. The sprayers 18 are horizontallyand piyotally,

adjustably mounted on a sprayer support 19 which in turn is verticallyadjustable along an extension 20 fixed atop a composite conduit zlrotatable on its own axis.

When the composite conduit 21 is revolved, the sprayers 18 each direct aspray onto the convex surface ofthe article 11 positioned axially of thecomposite conduit 21, the spray progressing around a conical pathandimpinging nearly normally upon all parts of the convex surface, asindicated by the broken lines in Figure I. The nearly normal impingementof the spray produces an extremely smooth and evenly applied coat ofpaint.

The composite conduit 21 in addition to rotating the sprayers 18 alsofunctions to supply thesprayers withpaint and air. A paint supply line22 carries paint from a source outside of the machine under pressure ofpreferably from two to ten pounds per square inch. to aninside conduit23 extending upwardly. through the composite conduit 21'. Thepaintflows-fromithe top ofztheinside.

conduit 23 through lines 24 to the sprayers 18. An air supply line 25carries air from a source outside of the machine under pressure ofpreferably from sixty to seventy-five pounds per square inch to anoutside conduit 26 extending upwardly and around the inside conduit 23.The air flows from the top of the outside conduit 26 through lines 27 tothe usual atomizing air inlet 28 in each of the sprayers 18. The air isdivided inside the sprayers 18, part being used for the usual triggerair and part being used for the usual atomizing air. The air pressurewithin the sprayers 18 closes a normally open exhaust valve 29 threadedinto the usual trigger air inlet in each of the sprayers, which valves29 open when the air pressure falls after the air has been cut otf atthe end of a spraying cycle. Opening of the exhaust valves 29 causes thesprays to cut olf sharply. The mechanism of the sprayers itself is notshown, since it is not part of the invention. Likewise, no controlmechanism is shown for turning on and off the paint supply to thesprayers and the air supply to the sprayers and to the air cylinder 14,since any suitable manual or automatic controls may be used and such arenot part of the invention.

The composite conduit 21 is rotated or revolved by means of powersupplied from an air motor 30 gear connected to a gear reducer 31 whichis gear connected in turn to the composite conduit. The air motor 30 andthe gear reducer 31 are mounted on a stand 32 supported from the framemember 3 and are shielded from deposits of paint by the frame member 2which is in the form of a shelf.

The gear connection between the gear reducer 31 and the compositeconduit 21 includes a gear 33 on the reducer cooperating with a gear 34fixed around the upper part of the outside conduit 26, as shown inenlarged detail in Figure 111. The upper part of the outside conduit 26is rotatably supported by a ball bearing mounting 35 having an outerrace 36 fixed to the top of the frame member 2 and an inner race 37fixed around the upper part of the outside conduit. The bearing mounting35 is shielded from deposits of paint by a shield 38 attached to theframe member 2.

When the upper part of the outside conduit 26 is turned by its gear 34,it turns in the bearing mounting 35 and a bearing section 39 of theoutside conduit turns on the flat face of a carbon seal 40 flexing on aball sphere 41 pressure sealed by an expansion thrust member 42. Theball sphere 41 is resiliently supported by springs 43 supported in turnby a lower non-rotating part 44 of the outside conduit 26. The bottom ofthe inside conduit 23 turns in spring loaded packing 45 and receivespaint under pressure from a threaded fitting 46 attached to the bottomof the non-rotating part 44 of the outside conduit 26. The top of theinside conduit 23 terminates in a T-fitting 47 atop which the extension20 is fixed. The directions of the flows of paint and air through theirrespective conduits are indicated by the arrows shown in Figures I andU1.

Another embodiment of the apparatus for rotating sprayers is illustratedin Figure IV. No rotatable composite conduit is used in thismodification, a sprayer support 19a being vertically adjustable along ashaft 48 rotatably mounted in suitably supported bearings 49. An articleheld in a mask 9a supported by a mask holding portion 6a of a roof 4a ofa cabinet 1a is given an evenly applied coat of paint by spray emittedfrom a pair of ordinary sprayers 18a so located within the cabinet 1a asto direct the sprays through the mask 9a. The sprayers 1841 arehorizontally and pivotally adjustably mounted on the sprayer support19a. When the shaft 48 is rotated or rocked, the sprayers 18a eachdirect a spray onto the convex surface of an article positioned axiallyof the shaft 48, the spray progressing around a conical path andimpinging nearly normally upon all parts of the convex surface, asindicated by the broken lines in Figure IV.

The shaft 48 is rocked by means of a pneumatically operated piston rod50 operatively attached thereto through a rack 51 cooperating with apinion 52 fixed to the shaft. The piston rod 50 may be reciprocatedwithin its air cylinder 53 by means of conventional automaticreciprocation valves and a cam 54 carried by the rack 51 may be used toactuate switches 55 to trigger the sprayers 18a. The length of thestroke of the reciprocating piston rod 50 can be varied causing thepinion 52 to be turned any number of degrees short of the number whichwill cause excessive twisting of flexible lines 56 supplying thesprayers 18:21 with paint and air. The flexible lines 56'are springconnected at 57 to a shield 58 protecting the mechanism below it fromdeposits of paint. A supporting frame member 2a of the cabinet 1afunctions as a further shield for the parts which lie below it fromdeposits of paint.

The sprayers 18a may be caused to rotate 360 degrees in one directionand then 360 degrees in the other direction or they may be caused torock only 180 degrees in one direction and then 180 degrees in the otherdirection with the sprayers, controlled by the switches 55, shut off onthe return trip if so desired. A travel of 180 degrees using twosprayers is very satisfactory, since the convex surface of the article1111 can be completely covered with paint and still the flexible lines56 are not appreciably twisted. The article 11a may be held in placeupon the mask 9a by fingers similar to the fingers 12 and 13 shown inFigure I, the operation and mounting of which have been hereinbeforedescribed.

, It is to be understood that the foregoing description and theaccompanying drawings are exemplary only and that the invention issusceptible to variation and modification within the spirit and scope ofthe subjoined claims.

Having described the invention, I claim:

1. In a spray painting machine for painting portions of objects havingnon-planar surfaces, an upper work supporting member having an opening,a closed cabinet including said member as the top thereof, a stationarymask in paint tight relationship to said upper member, said maskconforming to the non-planar surfaces of said objects and having an openportion in registry with said opening, a finger above said opening,means to advance said finger toward said opening to engage objects to bepainted to maintain said objects in tight engagement with saidconforming mask, a sprayer support in said cabinet rotatable about anaxis passing through said opening, a sprayer mounted on said support andradially spaced from said axis, said sprayer being oriented to direct aspray through the open portion of said mask, and means for rotating saidsupport and said sprayer about said axis.

2. In a spray painting machine for painting portions of objects havingnon-planar surfaces, an upper work supporting member having an opening,a closed cabinet including said member .as the top thereof, astationary, maskin paint tight relationship to said upper member,

said mask conforming to the non-planar surfaces ofsaid' objects andhaving an open portion in registry with said opening, a pair ofadjustably spaced fingers above'said' opening, means to force saidfingers against objects to be painted to maintain said objects in tightengagement with said conforming mask, a sprayer support rotatable aboutan axis passing through said opening, a sprayer support bar for spacinga sprayer radially from said axis and adjustably mounted for positioningalong said support within a range of separations from said opening, asprayer adjustably mounted on said support bar for positioning alongsaid bar in a range of radially spaced positions from said axis, meansfor pivoting said sprayer on said bar radially of said support andtoward the open portion ofsaid mask, and means for rotatingsaid support.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Burdick Aug. 19, 1919 Johnson et a1. Oct.24, 1933 6 Uden Apr. 3, 1934 Schweitzer Apr. 10, 1945 6 .Griffin Apr. 2,1946 Neal Oct. 25, 1949 Peeps Mar. 16, 1954 Szczepanski Nov. 30, 1954Ericks et a1 Dec. 7, 1954 Williams Feb. 1, 1955 Way et a1. Nov. 29, 1955

